The effects of auxine and cytokinin hormones on maize grain quality unde drought stress condition

This study was conducted to evaluate the effect of auxin and cytokinin spraying in different growth stages on grain composition of maize (KSC 704) under drought stress condition during 2013 growing season at Seed and Plant Improvement Institute, Karaj, Iran. The experiment was carried out in three separate environments included non-drought stress environment, drought stress in the vegetative stage and drought stress in the reproductive stage. In each environment, foliar application of cytokinin in three stages (control, V5 –V6 and V8-V10) and foliar application of auxin in three stages (control, silk emergence and 15 days after that) was laid out as a factorial design based on randomized complete block design with three replications. The results showed that the maximum protein (10.93%) and soluble sugar (5.80%) in grain were obtained under drought stress in the productive stage whereas the maximum starch (77.37%) and grain dry mater (90.83%) were obtained in non-stress condition. Foliar application of cytokinin in V8-V10 stage, increased convert starch to soluble sugar on the other hand, foliar application of auxin in silk emergence stage caused converting hexose sugars to starch, increasing the sink capacity (grain endosperm) for receiving more starch and also increasing the grain dry mater .